You can now set a background image in Teams. On the "..." menu, pick Show Background Effects. From there you can pick one of several on offer. My class enjoyed this one.
Right now they supposedly don't let you add your own custom images, but it turns out you can. After class I added a wallpaper image in my user profile AppData\Roaming\Microsoft\Teams\Backgrounds\Uploads
and Teams found it.
Also, a recent update added the ability for the meeting organizer to End Meeting. This is something I have been wanting, and it is super useful. Often a student will walk away from our class meeting without disconnecting, and even though I have stopped the recording, it does not show up in the stream until everyone has left the meeting. Now if there is anyone leftover at the end of our class meeting, I can just end it. (It's an option on the "..." menu.)
Department of Mathematics & Statistics
University of Vermont